What does the Mhrb in the lye bath look like? Ideally it should resemble a viscous liquid, i.e. no solid chunks or visible fibers. If it doesn't, your SWIM need not worry because the mix is still salvageable, and still full of spice. Your SWIM might want to take a suggestion from Lazyman's Tek: Use a (steel) potato masher to mash the Mhrb in the lye bath until there are no more solid chunks; do this without the naptha since you don't want to inadvertently make an emulsion. Then carry on as planned. Don't give up, keep us updated.
Also, ditto on the coffee grinder. That's the way to go.